After you delete or reverse a purchase order, you need to correct your stock records if you marked the order as delivered. 

Sage 50 Accounts uses the First In First Out (FIFO) system. This means you can't simply post an Adjustment Out (AO) for the quantity that has been incorrectly delivered, because the AO removes the oldest stock, not the stock that you've just delivered.

When using the AO option, to ensure correct retrospective product valuation reports, use the correct dates.

If either of the following are true, you can simply post an AO for the quantity delivered in error:

• The Quantity In Stock was zero before this delivery
• The Cost Price of the product has always been the same

If neither of these statements are true, you must:

• Adjust out the entire stock quantity so the Quantity In Stock is zero
• Adjust in the correct quantities using the required cost prices

There are two options for this:

The exact method

1. Click Products and services and select the relevant product then click Reports.
2. Click Product analysis and double-click the Product Activity report.
3. Leave all the Criteria Values as default then click OK.

Print the report and highlight or make a note of the following:

4. The first In transaction, for example AI or GI, where the Quantity Used is less than the Quantity.
5. Every other In transaction after the transaction located in step 4.
6. Don't highlight the GI from the incorrectly delivered purchase order.
7. Post an Adjustment out (AO) for the entire Quantity In Stock.
8. Calculate the difference between the Quantity and the Quantity Used for the transaction located is step 4.
   
   You must now post an Adjustment in (AI) transaction for each of the highlighted transactions, using the original Date, Ref, Quantity and Cost Prices that appear on the activity report.
   
   The Quantity for the first AI is the difference calculated in step 8.

    

The average cost price method

You must first calculate what the average cost price was before the stock was delivered incorrectly.

1. Click Products and services and select the relevant product and click Reports.
2. Click Product valuation and double-click the Product Valuation (Average Cost Price) report.
3. Leave all the Criteria options as default then click OK.
4. Make a note of the Quantity In Stock and the Stock Value.
   
   For calculation purposes, we'll call these Figure A and Figure B respectively. For example, Figure A = 163.00 and Figure B = 2766.15
   
   
5. Double-click the relevant product and click the Activity tab.
6. Locate the incorrect GI and make a note of the Qty In and the Cost Price.
7. For calculation purposes, we'll call these Figure C and Figure D respectively. For example, Figure C = 65.00 and Figure D = 36.45
8. The average cost price before the incorrect delivery can be calculated as follows:
   • [Figure B - (Figure C x Figure D)] / (Figure A - Figure C)
     
     

   Using the figures above as an example:

   • [2766.15 - (65 x 36.45)] / (163 - 65) = (2766.15 - 2369.25) / 98 = 4.05
     
     
9. Post an Adjustment out (AO) for the entire Quantity In Stock.
   You must now post an Adjustment in (AI) for the new quantity (Figure A - Figure C) using the average cost price calculated in step 8.